Question

I’ve created a basic MVC REST API to just get single Person from the datasource. It all works locally but not when I deploy it on to the server.

public JsonResult Get(int? id)
{
     if (id != null)
     {
           Person p = personBl.Get((int)id);
           return Json(p, JsonRequestBehavior.AllowGet);
     }

     return Json("");
}

My jquery call is as follows:

$.ajax({
            type: 'GET',
            url: 'http://localhost:50708/Persons/Get/',
            data: { id: 20 },
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: function (data) {
                alert(data.Name);
            }
        });

When I deploy it on to my windows 2003 server and call the Get function, it’s always 404 (obviously there’s no View attached as I just want the json).

I use a jsonp call as the server is on a different domain.

$.ajax({
            type: 'GET',
            url: 'http://192.168.1.187:1500/Persons/Get/',
            data: { id: 20 },
            contentType: "application/json; charset=utf-8",
            dataType: "jsonp",
            jsonpCallback: 'jsonpCallback'
        });

function jsonpCallback(data) {
    alert('callback');
}

Any idea why the above doesn’t seem to work?

Answer 1

I don’t see how you are using JSONP. Your server still returns plain JSON:

return Json(p, JsonRequestBehavior.AllowGet);

which will be sent like this over the wire:

{ firstName: 'John', lastName: 'Smith' }

A JSONP response would look like this:

callbackname({ firstName: 'John', lastName: 'Smith' })

It is not enough to only instruct the client about jsonp => the server needs to support it.

You may take a look at the following blog post and use the JsonpResult illustrated there on the server.